Amino Acid-Coated Nanoparticles for Preservation of Cut Roses: Formulation and Performance

Cut flowers undergo rapid physiological decline following harvest, driven by membrane degradation, oxidative stress, pigment loss, and reduced metabolic activity. Nanoparticle-based treatments offer a promising strategy to extend vase life, yet their effects in ornamental species remain poorly defined. The amino acid coatings were employed to enhance nanoparticle solubility, thereby facilitating the delivery of the micronutrients to the floral tissues. Here, we evaluate a suite of amino acid-coated nanoparticle formulations based on seven key micronutrients (Fe, Cu, Zn, Mn, Mg, Si, and Se) alongside synergistic multielement blends to determine their impact on postharvest performance in Avalanche Roses. Flowers were assessed for physiological, biochemical, and optical parameters, including water uptake, membrane stability index (MSI), malondialdehyde content, antioxidant enzyme activity, soluble sugars, and pigment profiles, alongside nanoparticle uptake quantification via X-ray fluorescence spectrometry and inductively coupled plasma-mass spectrometry. Nanoparticles based on Mn, Cu, and Fe significantly improved MSI, enhanced superoxide dismutase activity, and reduced lipid peroxidation compared with controls, indicating reduced oxidative stress. These treatments also promoted favorable pigment dynamics and increased fructose levels, with the lower-dose iron (10 mg/L) and the iron–manganese blend showing particularly strong combined benefits. In contrast, several higher-concentration treatments (copper, silicon, selenium, and magnesium) induced anthocyanin degradation, elevated phenolics, and lipid peroxidation, revealing clear toxicity thresholds.